Liquid crystal display devices have been widely used as displays of portable electronic devices such as mobile phones, television sets, personal computers, or the like. However, it has been known that the liquid crystal display devices are generally excellent in viewability from the front, whereas the viewing angle thereof is narrow, so various attempts for widening the viewing angle have been made. As one of these attempts, a configuration is considered in which a member (hereinafter, referred to as a light diffusion member) which diffuses light emitted from a display body such as a liquid crystal panel is provided on a viewing side of the display body.
For example, PTL 1 discloses an optical sheet including a base film layer, an optical functional sheet layer disposed on the base film layer, and a diffusion material containing layer disposed on the optical functional sheet layer. In the optical sheet, the optical functional sheet layer has prism portions of a substantially trapezoidal shape formed in parallel along an upper surface of the base film layer and a light absorbing portion is disposed in a substantially wedge-shaped portion between the prism portions.